<?php
/**
 * Event.
 *
 * @package ElevenRank
 * @since   1.0.0
 */

namespace ElevenRank\Modules\Schema;

use WP_Post;

defined( 'ABSPATH' ) || exit;

/**
 * An event needs a name, a start and a place with an address (Google's Event rules). An online
 * event has an online address instead; one that is both has both.
 *
 * @since 1.0.0
 */
final class Event_Node extends Content_Node {

	/**
	 * Builds the node.
	 *
	 * @since 1.0.0
	 *
	 * @param string               $type   Event.
	 * @param array<string, mixed> $fields Field values.
	 * @param WP_Post              $post   The post.
	 * @param Node_Context         $c      Page information.
	 * @param Graph                $graph  The graph.
	 * @return array<string, mixed>|null
	 */
	public function build( string $type, array $fields, WP_Post $post, Node_Context $c, Graph $graph ): ?array {
		$name  = $this->text( $fields, 'name', $this->title( $post ) );
		$start = $this->text( $fields, 'start' );
		$mode  = $this->text( $fields, 'attendance', 'offline' );

		$place   = 'online' !== $mode ? $this->place( $fields ) : null;
		$virtual = 'offline' !== $mode ? $this->virtual_location( $fields ) : null;

		if ( '' === $name || '' === $start || ( null === $place && null === $virtual ) ) {
			return null;
		}

		$location  = array_values( array_filter( array( $place, $virtual ) ) );
		$status    = $this->text( $fields, 'status' );
		$organizer = $this->text( $fields, 'organizer_name' );

		return array(
			'@type'               => 'Event',
			'@id'                 => $c->id( 'event' ),
			'mainEntityOfPage'    => array( '@id' => $c->id( 'webpage' ) ),
			'name'                => $name,
			'startDate'           => $start,
			'endDate'             => $this->text( $fields, 'end' ),
			'eventStatus'         => '' !== $status ? 'https://schema.org/' . $status : null,
			'eventAttendanceMode' => 'https://schema.org/' . ucfirst( $mode ) . 'EventAttendanceMode',
			'location'            => 1 === count( $location ) ? $location[0] : $location,
			'description'         => $this->text( $fields, 'description', $this->description( $post, $c ) ),
			'image'               => $this->image_url( $fields, 'image', $post ),
			'organizer'           => '' !== $organizer ? array(
				'@type' => 'Organization',
				'name'  => $organizer,
				'url'   => $this->text( $fields, 'organizer_url' ),
			) : null,
			'offers'              => $this->offer( $fields, 'offer_', $c->url ),
		);
	}

	/**
	 * The Place, only with an address.
	 *
	 * @since 1.0.0
	 *
	 * @param array<string, mixed> $fields Field values.
	 * @return array<string, mixed>|null
	 */
	private function place( array $fields ): ?array {
		$street = $this->text( $fields, 'street' );
		$city   = $this->text( $fields, 'city' );

		if ( '' === $street && '' === $city ) {
			return null;
		}

		return array(
			'@type'   => 'Place',
			'name'    => $this->text( $fields, 'location_name' ),
			'address' => array(
				'@type'           => 'PostalAddress',
				'streetAddress'   => $street,
				'addressLocality' => $city,
				'addressRegion'   => $this->text( $fields, 'region' ),
				'postalCode'      => $this->text( $fields, 'postal_code' ),
				'addressCountry'  => $this->text( $fields, 'country' ),
			),
		);
	}

	/**
	 * The online location.
	 *
	 * @since 1.0.0
	 *
	 * @param array<string, mixed> $fields Field values.
	 * @return array<string, mixed>|null
	 */
	private function virtual_location( array $fields ): ?array {
		$url = $this->text( $fields, 'online_url' );

		return '' === $url ? null : array(
			'@type' => 'VirtualLocation',
			'url'   => $url,
		);
	}
}